Sir Alex Ferguson claims the Premier League is the only trophy that "really does matter" to Manchester United, insisting winning the title will help ease the disappointment of their FA Cup and Champions League exits.

United face a derby clash against Manchester City on Sunday hoping to extend their league lead to 18 points, although the current gap already seems unassailable.

Although he has remained modest about his side wrapping up the title well before the final day of the season, Ferguson has finally admitted the league trophy is heading to Old Trafford for the 20th time in their history.

"In the context of the kind of competition we have, teams from London -
Tottenham, Arsenal and Chelsea - Liverpool and Everton, there are massive
challenges every year," Ferguson told MUTV. "For every one of those teams, their supporters hope they win one trophy. We have won the one that really does matter to our fans.

"Yes, I would have loved to win the European Cup again but we got knocked out
in circumstances that everyone is still talking about, and the disappointment of
getting knocked out by Chelsea is obvious. But the league form has been consistent."

While United have the best attack in the league this season, with 70 goals scored, their defence has been a standout in recent weeks, helping David de Gea keep six consecutive clean sheets in the Premier League heading into the derby.

Although de Gea was heavily criticised in his early days at Old Trafford, team-mate Rio Ferdinand believes the Spaniard has done well to rise above the pressure.

"When you are a keeper, experience comes with games and becoming used to
certain situations," Ferdinand said. "He hasn't been here long. He is young, he had to become accustomed to his new
surroundings and he wasn't given time.

"When you play for Manchester United you are under incredible scrutiny. That is just the way it is. You have to get used to it. You need a thick skin to be a Manchester United
player. Because if you cannot take a battering at times you will fall by the
wayside and someone else will fill your shoes.

"He has a huge price tag on his head that carries a lot of weight. But he is resilient, even if he still has a lot to prove because this season
is not over yet."